FREE NEET Biology Practice MCQ Test: Plant Growth And Development Exercise 1 Questions Answers With Detailed Explanations [PDF]

Answer: (c)

Answer: (b)

Answer: (d)

Answer: (c)

Answer: (a)

Answer: (a)

Answer: (a)

Answer: (a)

Flowering is induced by light and temperature.

Answer: (d)

Ethylene is produced from amino acid methionine. Kinetin is a modified form of adenine, (purine).

Answer: (a)

Answer: (b)

Answer: (c)

Answer: (c)

Answer: (c)

Cytokinin has a very specific effect on cell division (cytokinesis), hence the name cytokinin. They contain kinetin and related compound generally called kinins. Chemically, cytokinins are degradation product of adenine, ATP, NAD and NADP. Cytokinins are essential for cytokinesis though chromosome doubling can occur in their absence. Cytokinins bring about division even in permanent cells.

Answer: (d)

Barley seeds are associated with α-amylase bioassay of gibberellins.

Answer: (d)

The effect of photoperiods or daily duration of light hours (and dark periods) on the growth and development of plants, especially flowering, is called photoperiodism. Photoperiodism was first studied by Garner and Allard (1920). They observed that 'Maryland Mammoth' variety of tobacco could be made to flower in summer by reducing the light hours with artificial darkening. It could be made to remain vegetative in winter by providing extra light.

Answer: (d)

Answer: (b)

Abscissic acid (ABA), also known as abscisin II and dormin, is usually found in vascular plants, some fungi and some green algae. It is a multipurpose plant hormone which acts as an inhibitor because it opposes the growth of promoting effect of auxins, GA and cytokinins, thus keep their activity under control. ABA is also known as stress hormone because it is produced under conditions of stress and causes partial closure of stomata under drought and thus acts as anti-transpirant.

Answer: (c)

Answer: (a)

Abscisic acid is produced during water stress that brings stomatal closure. Abscisic acid is a stress hormone and it is produced during water scarcity, when the transpiration rate exceeds absorption, the plant faces water stress conditions. As a result, incipient wilting occurs. Under water stress conditions ABA increases which induces stomatal closure.